Summary: On External­Memory MST, SSSP and
Multi­way Planar Graph Separation
(Extended Abstract)
Lars Arge 1;? , Gerth Stølting Brodal 2;?? , and Laura Toma 1;? ? ?
1 Duke University, Durham, NC 27708--0129, USA
2 University of Aarhus, DK­8000  Arhus C, Denmark
Abstract. Recently external memory graph algorithms have received
considerable attention because massive graphs arise naturally in many
applications involving massive data sets. Even though a large number of
I/O­efficient graph algorithms have been developed, a number of funda­
mental problems still remain open. In this paper we develop an improved
algorithm for the problem of computing a minimum spanning tree of a
general graph, as well as new algorithms for the single source shortest
paths and the multi­way graph separation problems on planar graphs.
1 Introduction
Recently external memory graph algorithms have received considerable attention
because massive graphs arise naturally in many applications involving massive
data sets. One example of a massive graph is AT&T's 20TB phone­call data
graph [11]. Other examples of massive graphs arise in Geographic Information
Systems (GIS). For instance, GIS terrains are often represented using planar